diff --git a/dm5/dm5.opam b/dm5/dm5.opam
new file mode 100644
index 0000000..a43bbcb
--- /dev/null
+++ b/dm5/dm5.opam
@@ -0,0 +1,32 @@
+# This file is generated by dune, edit dune-project instead
+opam-version: "2.0"
+synopsis: "A short synopsis"
+description: "A longer description"
+maintainer: ["Maintainer Name <maintainer@example.com>"]
+authors: ["Author Name <author@example.com>"]
+license: "LICENSE"
+tags: ["add topics" "to describe" "your" "project"]
+homepage: "https://github.com/username/reponame"
+doc: "https://url/to/documentation"
+bug-reports: "https://github.com/username/reponame/issues"
+depends: [
+  "dune" {>= "3.20"}
+  "ocaml"
+  "odoc" {with-doc}
+]
+build: [
+  ["dune" "subst"] {dev}
+  [
+    "dune"
+    "build"
+    "-p"
+    name
+    "-j"
+    jobs
+    "@install"
+    "@runtest" {with-test}
+    "@doc" {with-doc}
+  ]
+]
+dev-repo: "git+https://github.com/username/reponame.git"
+x-maintenance-intent: ["(latest)"]
diff --git a/dm5/dune-project b/dm5/dune-project
new file mode 100644
index 0000000..52a81e5
--- /dev/null
+++ b/dm5/dune-project
@@ -0,0 +1,26 @@
+(lang dune 3.20)
+
+(name dm5)
+
+(generate_opam_files true)
+
+(source
+ (github username/reponame))
+
+(authors "Author Name <author@example.com>")
+
+(maintainers "Maintainer Name <maintainer@example.com>")
+
+(license LICENSE)
+
+(documentation https://url/to/documentation)
+
+(package
+ (name dm5)
+ (synopsis "A short synopsis")
+ (description "A longer description")
+ (depends ocaml)
+ (tags
+  ("add topics" "to describe" your project)))
+
+; See the complete stanza docs at https://dune.readthedocs.io/en/stable/reference/dune-project/index.html
diff --git a/dm5/lib/dune b/dm5/lib/dune
new file mode 100644
index 0000000..794f940
--- /dev/null
+++ b/dm5/lib/dune
@@ -0,0 +1,3 @@
+(library
+ (name lib)
+ (public_name dm5))
diff --git a/dm5/lib/lib.ml b/dm5/lib/lib.ml
new file mode 100644
index 0000000..b099e71
--- /dev/null
+++ b/dm5/lib/lib.ml
@@ -0,0 +1,131 @@
+(* Exercice 0 *)
+let zip ta tb = Array.map2 (fun a b -> a,b) ta tb;;
+
+(* Exercice 1 *)
+let tirette t =
+  let n = Array.length t in
+  Array.init (n/2) (fun i -> t.(i) + t.(n-i))
+;;
+
+(* Exercice 2 *)
+let quarante_deux t =
+  let n = Array.length t in
+  let count = ref 0 in
+  let i = ref 0 in
+  while !i < n do
+    if t.(!i) mod 42 = 0 then
+      count := !count + 1
+    else ()
+  done;
+  !count
+;;
+
+(* Exercice 3 *)
+let croissant t =
+  let n = Array.length t in
+  let i = ref 0 in
+  while !i+1 < n && t.(!i) <= t.(!i+1) do
+    i := !i+1
+  done;
+  !i
+;;
+
+(* Exercice 4 *)
+let bitonique t =
+  let n = Array.length t in
+  let grows = ref true in
+  let i = ref 0 in
+  let res = ref true in
+  while !res && !i+1 < n do
+    if !grows then
+      (if t.(!i) > t.(!i+1) then
+        grows := false)
+    else
+      if t.(!i) < t.(!i+1) then
+        res := false
+  done;
+  !res
+;;
+
+(* Exercice 5 *)
+let psrn ta tb = Array.fold_left
+  (fun acc (a,b) -> acc + (a*b))
+  0
+  (Array.map2
+    (fun a b -> a,b)
+    ta
+    tb
+  )
+;;
+
+
+
+(* Exercice 6 *)
+let rotation m =
+  let nx = Array.length m in
+  if nx = 0 then [||] else
+  let ny = Array.length m.(0) in
+  Array.init_matrix
+    ny
+    nx
+    (fun x y -> m.(y).(ny-x-1))
+;;
+
+(* Exercice 7 *)
+let plsci t =
+  let n = Array.length t in
+  let current_start = ref 0 in
+  let start = ref 0 in
+  let max_length = ref (min 1 n) in
+  for i = 0 to n-1 do
+    if i+1 = n || t.(i) != t.(i+1) then (
+      let length = i - !current_start + 1 in
+      if !max_length < length then (
+        max_length := length;
+        start := !current_start
+      );
+      current_start := i+1
+    )
+  done;
+  !start, !max_length
+;;
+
+(* Exercice 8 *)
+let sorteren t =
+  let zero, one, two = Array.fold_left
+    (fun (zero, one, two) a -> match a with
+      | 0 -> zero+1,one,two
+      | 1 -> zero,one+1,two
+      | 2 -> zero,one,two+1
+      | _ -> invalid_arg ""
+    )
+    (0,0,0)
+    t
+  in
+  Array.init
+    (zero+one+two)
+    (fun i ->
+      if i < zero then 0
+      else if i < zero+one then 1
+      else 2
+    )
+;;
+
+(* Exercice 9 *)
+let dominant s =
+  let counts = Array.make 0 126 in
+  String.iter (fun c ->
+    let c = Char.code c in
+    counts.(c) <- counts.(c) + 1;
+  ) s;
+  let _, max_c =
+    Array.fold_left
+      (fun (c, max_c) a ->
+        c+1,
+        if a > counts.(max_c) then c else max_c
+      )
+      (0,0)
+      counts
+  in
+  Char.chr max_c
+;;
diff --git a/dm5/test/dune b/dm5/test/dune
new file mode 100644
index 0000000..d2d6441
--- /dev/null
+++ b/dm5/test/dune
@@ -0,0 +1,4 @@
+(executable
+ (name test)
+ (public_name test)
+ (libraries lib))
diff --git a/dm5/test/test.ml b/dm5/test/test.ml
new file mode 100644
index 0000000..8a76543
--- /dev/null
+++ b/dm5/test/test.ml
@@ -0,0 +1,22 @@
+open Lib;;
+
+assert (rotation
+  [|
+    [| 1; 5; 9 |];
+    [| 2; 6; 10 |];
+    [| 3; 7; 11 |];
+    [| 4; 8; 12 |]
+  |]
+  =
+  [|
+    [| 9; 10; 11; 12 |];
+    [| 5; 6; 7; 8 |];
+    [| 1; 2; 3; 4 |]
+  |]
+);;
+assert (rotation [||] = [||]);;
+assert (rotation [|[||]; [||]|] = [||]);;
+
+assert (plsci [||] = (0,0));;
+assert (plsci [|1|] = (0,1));;
+assert (plsci [|1; 1|] = (0,2));;